If you get the error: "the trust relationship between this workstation and the primary domain failed" you can use NETDOM.EXE from the Remote Server Administration Tools to fix it. The command is as follows: netdom resetpwd /s:server /ud:user /pd:*

You will have to know the username and password of an administrative user, but it should work.

If you are using Windows 7 and don't have the Remote Server Administration Tools installed, you can download them from Microsoft's website here.